LeetCode 7. Reverse Integer C++

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Given a 32-bit signed integer, reverse digits of an integer.

Example 1:

Input: 123
Output: 321

Example 2:

Input: -123
Output: -321

Example 3:

Input: 120
Output: 21

Note:
Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−2^31,  2^31 − 1]. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.

class Solution {
public:
    int reverse(int x) {
        int res=0;
        while(x){
            int pop=x%10;            
            if(res>INT_MAX/10 || res<INT_MIN/10)
                return 0;
            res=res*10+pop;
            x/=10;
        }    	
	    return res;        
    }
};

神奇地通过了，感觉循环最后要加个判断：if (rev == INT_MAX / 10 && pop > 7)、if(rev == INT_MIN / 10 && pop < -8)

还有一个思路：

long long int res = 0，pop = 0；

最后和INT_MAX、INT_MIN比较大小